title: Outflow tract ventricular tachycardia mapped to the coronary arteries: anatomical correlates and management strategies.
abstract: BACKGROUND
  The coronary cusps have been well described as a successful site for ablation in patients with symptomatic outflow tract ventricular tachycardia. The earliest site of activation is rarely found at the ostia or into the main coronary arteries. The exact anatomic substrate, diagnostic characteristics, and therapeutic approaches for such instances are poorly understood.
  
  
  METHODS
  We retrospectively reviewed outflow tract ventricular arrhythmia (OTVA) ablations done at Mayo Clinic Rochester from 2003 to 2011 (total VT: 414; outflow tract VT: 106). Three cases were identified where the earliest site of activation was not within the cusp but rather at or within the coronary ostia (3/414 for all VT: 0.7%; 3/106 for all OTVT: 2.8%).
  
  
  RESULTS
  In 1 patient, the left main coronary artery (LMCA) was found to have electrograms (EGMs) recorded with bipolar mapping that preceded activation in the cusps or the left ventricular outflow tract. In 2 cases, the right coronary ostium and proximal right coronary artery recorded the earliest signals. Intracardiac echocardiographic guidance was used to successfully ablate these arrhythmias targeting the aortic route (1 patient) or the right coronary cusp (2 patients), and essentially isolated the focus of origin from the ventricular outflow tracts. Detailed mapping of surrounding structures, including the atrial appendages, the contralateral outflow tract, and the coronary venous system excluded far-field mapping in the artery as a cause for early activation at the ostial location. Local EGM characteristics suggested an unusually lengthy supravalvar myocardial extension as the likely arrhythmogenic substrate. Ablation was successful without coronary arterial or valvular injury and without valvular or root stenosis.
  
  
  CONCLUSIONS
  Endocardial ablation isolating foci of origin in the vicinity of the coronary ostia is a challenging procedure but can be performed safely with appropriate visualization and is effective in the treatment of OTVA.
authors.affiliation: Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Vaibhav
authors.initials: V
authors.lastname: Vaidya
authors.forename: Faisal
authors.initials: F
authors.lastname: Syed
authors.forename: Christopher
authors.initials: C
authors.lastname: Desimone
authors.forename: Sami
authors.initials: S
authors.lastname: Bdeir
authors.forename: Freddy Del Carpio
authors.initials: Fdel C
authors.lastname: Munoz
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Packer
authors.forename: Samuel J
authors.initials: SJ
authors.lastname: Asirvatham
mesh_terms: D000200:Action Potentials; D000328:Adult; D017115:Catheter Ablation; D003331:Coronary Vessels / Q000503:physiopathology* / Q000601:surgery; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008910:Minnesota; D012189:Retrospective Studies; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D016896:Treatment Outcome
keywords: aortic sinus of Valsalva; catheter ablation; left ventricular outflow tract; ventricular tachycardia